Roofing systems for flat roof structures are well known as shown by U.S. Pat. Nos. 4,045,922; 4,162,597 and 4,424,650. These systems provide adequate covering for flat roofs, but tend to be expensive to install. A roofing system is needed which will provide a replacement roof for roofs with split seams, rusted surfaces, poor insulating properties or leaking joints, but at a low cost to accommodate the modest income level of many mobile home owners.